Hi, I was discussing cycling with my dear friend, Tim, and in no time at all we were at loggerheads with regard to weight savings as it relates to performance increases. Tim is of the opinion that "mass is mass" no matter where on the bike/person it is (controlling for aerodynamics etc.) but I am of the opinion that mass in certain places actually inhibits one's cycling ability much more than if the mass were in another location. One example that I thought of was the mass of the crank arms, pedals, and shoes of the rider. A typical fit cyclist is probably cruising along the road at a pedalling cadence of, let's say, 100 rpm. The "rotational velocity" of the pedals, or whatever your might call it, isn't usually static as a person is probably accelerating and decelerating constantly, but even if it was, it seems to me that a person is needing to perform more work to rotate that extra mass around its axis than if the weight were, for example, located on Tim's not insubstantial gut. Another option, I suppose, is that the force of gravity acting upon the front pedal's mass balances out the extra work needed to fight gravity on the way up for the opposing pedal. The point of the discussion is that weight savings in cycling is an expensive endeavor where one may pay dearly for a savings of only a few grams. Those grams, when examined in relation to the mass of the rider as a whole do not seem to be all that consequential, unless they are somehow "heavier" in certain spots than they are in others, i.e. the crank arms etc. Could anyone enlighten us further?